Control for steam turbines



, .Y 1,625,004 Aprll 19 1927- c, R. WALLER CONTROL FOR STEAM TURBIN'ES Filed July 51, A1922 s sheets-sheet 1 l 1,625,004 April 19, 1927. i C. R. *WALLER CONTROL FOR STEAM TURBINES Filednuly :51, 1922 s sneets-shet 2 CONTROL FOR STEAM TURBINES Filed July 31, 1922 3 Sheets-Sheet 5 Patented pr. 19, 1927.

UNITED STATES PAT-ENT OFFICE.

,CARL R. WALLER. `or rRiiN'roia, NEW JERSEY, assienoR fro DE 4Lavar.STEAM TUR- Brnn ,CQMPANY or Tnmi'roii, new JnRsRY, n c eRPoRArroN or New Vannessi.

lCONTROL FOR s Application filed July 31, 192,2.

This invention .relates to control devices vfor steam turbines and more particularly relates to means for varying the effective nozzle area of one or more of the diaphragms. Insteani turbines .of the bleeder type trom which a large amount of steam is .bled from a point intermediate the inlet and outlet of vthe turbine, it is necessary in order to obtain the highest eliiciency Vto vary the nozzle area in at 'least some ot the diaphragms.

IThe object of my invention is ,to provide a simple and eflicient means i'or varying the effective nozzle area ,of one or more of the diaphragme to substantially maintain a predetermined pressure in one or more ot vthe chambers or the bleed passage.

The vprecise nature of my invention will l be y.best understood by reference kto the accompanying drawings, it being premised, however, that changes may be made in the details of construction vwithout departing 'from the .spirit and scope of 4my invention as deinedinthe ap )ended claims.

Fig. 1 is a sectional view ,of a portion Iot a .steam .turbine with one form of my con-l trol device shown in connection therewith.

tFig. 2 is a similar sectional view at right angles Lto -Fig. l.

Fig. 3 vis a detail sectional view through one Iof .the control valves.

Figmet is a detail Isectional view of a master Valve on a larger scale lthan that shown -in F ig. 2.

Fig. 5 is a kdetail sectional view on the line 5-5 of Fig. 4.

'Fi-g. 6 is la face view of the vhandle Yfor Aactuating a master valve.

In these drawings, the reference character .6, 6 designates a two-partcasing of the .turbine, and 7 is Aa shaft rotatably mounted therein. 8a, 8b and 8 4are three turbine wheels, which, together with six other such wheels, are secured to the shatt 7.

The casing 6 is provided with dividing Awalls 9 and 10. -11 isa chamber in front of wall 9 in which is located the first turbine wheel and a diaphragm therefor, and which wheel is also secured -to shaft 7. 12% 12b and 12c are diaphragms in front ,of the wheels 8, 8b andS, respectively. The diaphragm 12d `ismounted in ,wall 9, whilediaphragms 12b, 12C, as well as six other dia- .phragms, similar to diaphragm 12C, are

TEAM TURBIN'ES.

Serial No. 578,573.

mounted in the wall or parti-tion 10. Each diaphragm is located in front of its wheel and isv .provided with nozzles for directing the steam to the vanes .ot its wheel. A13a and 131 are shaft-packing rings between the different stages and within their respective diaphragme 12Pand 12b. 14 is a chamber be'- tween walls 9 and 10 ,and diaphragme 12 and 12b, and is provided with a bleed outlet 14a, through which steam Vis bl-ed.

Diaphragm 12c and those vbeyond said diaphragm Aare provided with the usual nozzles 16 for directing the steam to the vanes of their V4wheels. Diaphragme 12a and 12". however, are each4 provided with several sets ofnozzles.

Diaphragm .12b is 4provided with seven sets ot nozzles 17, 17, 17C, 17d. 17e, 17f and 17g. Nozzles 1-7,communicate directly with chamber 14, while the other sets or nozzles communicate with Inozzle chambers 18h, 18, 18d, 18f'and 18g, respectively in the diaphragm 12b.

Steam is admitted to each otchambers 18b to 18g from chamber 14, lthrough a port which is opened and ,closed by a control valve, such as shown Ein 5F ig. 3. Nozzle chambers 18 to l8f are merely provided with a single valve-controlled port, while chamber 18g .is controlled by means `ot :two such ports and valves, as clearly .shown in Fig. 2.

In Fig. 3 I have shown, for example, a section vthrough the valve and its actuating mechanism for controlling the admission of luidto chamber 18b in diaphragm 12", which f1 Will now describe.

'Threaded in an opening in the diaphragm 12b`is a port member 19 vvhaving a central @boss 20 connected thereto by means ot' in tegral .spider arms.

Connected to this boss 20 by means of a threaded extension 21 is a support having ancexternally threaded head 22. I

2,3 is a circularlcollapsible,diaphragm connected .at one end to head 22 yby a ianged ring 24, while the other end ot said diaphragm is secured topa `valve 25 byra nut 26. Surrounding the extension 21 and interposed between the head 22 and valve 25 is a spring 27, which tends to retain the valve on lvits seat kon port member 19 and prevent the admissionxof steam tov chamber 18b when the valve is seated.

The endsofthe collapsible diaphragm are fit1 lil

connected to head member 22 and valve 25 so as to form steam-tight joints and to form a pressure chamber 28 Within the collapsible diaphragm, Which is in communication at one end With chamber 18h through the opening in the valve 25 through which the extension 21 extends. The other end of this diaphragm chamber 28 is in communication with a master valve mechanism 29 through a pipe 30, see Fig. 2.

When all the valves 25 carried by diaphragm 12b are closed, the only nozzles Which direct steam to the vanes of wheel 8" are nozzles of the set 17', vvhicb are always open.

Vfhen it is desired to open any oi' the valves 25 to admit steam to any or all oi' chambers 18h to 18g, pressure is exhausted from the chambers 28 through pipes 30, as hereinafter described, and as the outlet through pipes 30 is considerably greater than the area oi' opening through the valves, the pressure on the under sides of the valves will raise them from their seats against the action ot their springs 27 and permit a :tree liovv of steam from chamber 14 through the opened ports linto the nozzle chambers 13" to 18g.

rlhe diaphragm 12a is provided with similar sets of nozzles and nozzle chambers provided with control valves 31, which valves are in turn controlled from a master valve 32, Which is identical with valve 29.

The master valve shown in Figs. 4 to G comprises a casing 33, Which is secured to easing 6. 34 is a head closing one end of a chamber 35, and in which chamber is rotatably mounted a. valve member 3G. The valve 36 is connected to a valve stem 37, which passes through a stuiiing box 33 in the head 34. 39 is a valve-operating handle on the outer' end ot stem 37, the hub of which is rotatably mounted in a bearingsupporting member 40, supported by extensions from the head 34. 4()a is a. springpressed locking lever on handle 39 having a projection arranged to be seated in any one olf seven detents 41 in the body of the bearing for the handle, whereby the valve 36 may be locked in any one ot seven positions :tor the purpose hereinafter described.

rlfhe handle 39 is also provided Wit-h a pointer 42 Which is arranged to move over a graduated plate 43 on the bearing 40, and on which plate are numerals 1 to 6. The various members are so arranged that when the pointer 42 points to a numeral on plate 43, the numeral indicates the number ot' control valves that are open.

rlille valve easing 33 is provided With six ports 44", 44C, 44d, 44e, 44i and 44g, which communicate with chamber 35 in the valve casing and are also each connected, by a pipe 30, with pressure chambers 28 communicating with chamber 13b to 18g, respecneeaoofi tively, in the diaphragm 12b. 45 is a pipe connecting the chamber 35 in the valve cas ing 33 with a loiv pressure chamber' of the turbine, which in this case is chamber 15. 4G is a similar pipe connecting the chamber ot master valve 32 with pipe 45. The valve 3G is provided With a cut-away portion as shown in Fig. 5, whereby the ports 44h to 44g are successively placed in ccmmunication with chamber 35, or cut ott therefrom, in reverse order.

ln the drawings as the parts are set by master valve 3Q, chambers 18", 13 and 18(1 are open to steam iti-om chamber 14, while the valves ot chambers 80, 131' and 13g are closed so that steam is delivered to Wheel Sb through nozzles 17a to 17d, but not through nozzles 1Q, lil' and 17g.

ii handle 39 is shifted coiuiter-clocluvise one notch to bring pointer 42, opposite the numeral 2 on plate 43, valve 36 will be shifted to cover port 44. fifhis covering of port 44d iviil permit pressure to build up in chamber 28 which is in communication with chamber 13 above valve 25 controlling the port leading to chamber 18, and as soon as the pressure therein, plus the pressure et spring 2'? therein, exceeds the steam pressure ou the bottom of the said I valve, said valve will close and cut oit the supply oi? steam to chamber 13d. lt handle 39 is moved clockwise one point from that shown in Fig. G, valve 3G will also be shifted clockwise one point trom that shown in Fig. 5 and open port 44e to exhaust through pipe 45 with the loiv pressure chamber 15. rlhis opening oi' port 44@ to exhaust Will exhaust the pressure in diaphragm chamber 28 above control valve 25 tor the port of nozzle chamber 130, and as soon as the pressure therein, plus the spring pressure, is reduced below the steam pressure on the under side ot the said valve 25, said valve Will be opened by the steam pressure and steam Will new be adn'iitted to nozzle chambers 13b, 18, 181 and 18e from chamber 14.

ln the operation of the turbine shown, steam is admitted through the iirst diaphragm to the first Wheel to chamber 11. From chamber 11 the steam passes through the open nozzles in diaphragm 12a, into chamber 14. Some ot the steam is bled from chamber 14 through opening 14d for the purpose tor Which it is to be used, While the remainder passes through the open nozzles in diaphragm 12b, and between the vanes ot' Wheel 8', and then through the nozzles in the successive diaphragms and Wheels to chamber 15, from which the steam passes to exhaust.

Assuming that the turbine is developing 80% load and that 10% of the steam is dravvn through opening 14L and at which time the pressure in chamber 11 is 100 lbs., and the pressure in chamber 14 is GO lbs.,

which would mean that steam is extracted from the turbine through opening 14, at GO lbs. pressure:

Should the demand increase, the pressure in chamber h would drop, and to restore the pressure in said chan'iber, one or more .ot valves controlling' the ports to the vnozzle chambers in diaphragm 12" are .closed to reduce the nozzle area ot diaohragm 12b.

lt will also be understood that the pressure .in chamber ll may also be controlled by the control valves in diaphragm l2, through the medium of the master valve 32.

rEhe advantages ot my invent-ion result from the pro *'ision ot means for varying the nozzle area of one or more of the diaphragms ot a steam turbine from a single point ot control, whereby the nozzle area may readily be increased or decreased in stages rom the minimum area to the ina.Y innun area to control the pressure in a pi tor extracted steam determined stage or chamber ot the turbine, and thereby deliver steam to a point of use at a substantially unitorn'i pressure between the pressures ot the steam at the inlet and outlet` ends of the turbine.

Another advantage results from the 'provision of a control valve arrangement tor the nozzles, together with a. master valve, whereby the control valves are actuated by steam pressure controlled by the master valve.

A still further advantage results :from the provision oit' control valves which are actuated by the steam passing through the turbine, whereby am enabled to dispense with mechanically actuated mechanism, which enables me to provide simple, e'eotive, readily operated controlling means for actuating the control valves, and which controlling means can be operated with a minimum amount ot etiort by the engineer.

Having now fully described my invention, what claim and desire to protect by Letters Patent is:

l. A separating diaphragm for insertion in a turbine casing for separating a pressure chamber in the casing Yfrom another pressure chamber in the casing, havinga plurality of nozzle chambers therein provided with nozzles opening throne-h one side of the diaphragm, each chamber having a port opening through the other side ot the diaphragm, and fluid pressure actuated means for each valve connected thereto and supported on thel diaphragm and arrai @ged to be located within a pressure chamber in the turbine casing. A

2. A steam turbine having a casing, diaphragme therein dividing the casing into high pressure, low pressure and intermediate pressure chambers, there being a steam bleed leading from the intermediate pressure chamber, a rotor having a blade in each pressure chamber, there being a Vplurality of nozzle chambers in rone oit the diaphragme, each `having nozzles opening' into the adjacent chamber `of lower pressure, there being a port con'in'iunicating with each nozzle chamber and the adjacent. higher pressure chamber, a valve for controlling each port mounted. on the diaphragm a separatesteain pressure .actuated valveactuating mechanism tor each valve mounted von the ldiaphragm within a pressure chamber, a master valve, steam connections between the master valve and each ot the valve actuating meehanisms, and means for actuating the master valve tor controlling the opening and closing ot the valves ,tor the ports.

3. A steam turbine having a casing, dian pl'iragms therein dividing the casing into high pressure, low pressure and intern'iediate pressure chambers, there being a steam bleed leading from the intermediate pressure chamber, a rotor having a blade in each pressure chamber, there being a plurality of nozzle chambers in each of the diaphragme, each having nozzles opening into the adjacent chamber ot lower pressure, there being a port con'nnunicating with each nozzle chamber and the adjacent higher pressure chamber, a valve for controlling each port mounted on its diaphragm, a separate steam pressure actuated valve-actuating mechanism for each valve mounted on its diaphragm, two master valves, steam connections between one master valve and each of the valve actuating mechanisms on one diaphragm, similar connrctions between the second master valve and the valve actuating mechanisms on the other diaphragm, and means for actuating each of the master valves for closing and opening the ports.

d. A steam turbine having a casing, diaphragms therein dividing the casing into high pressure, low pressure and intermediate pressure chambers, there being a steam bleed leading from the intermediate pressure chamber, a rotor having a blade in each pressure chamber, there being a plurality of nozzle chambers in one of the diaphragms, each having nozzles opening into the adjacent chamber of lower pressure, there being a port communicating with each nozzle chamber and the adjacent higher pressure chan'iber, a valve for controlling each port mounted on the diaphragm, a separate steam pressure actuated valve-actuating mechanism for each valve mounted on the diaphragm and within a pressure chamber, a master valve within the casing, steam connections between the master valve and each of the valve actuating mechanisms, and a valve stem extending from the master valve outwardly through the valve casing.

5. A separating diaphragm it'or insertion in a turbine casing for separating a pressure chamber in the easing from another ypressure chamber in the casing, having a plurality of nozzle chambers therein provided with nozzles opening through one side of the diaphragm7 a Valve for each port Carried by the diaphragm, a collapsible diaphragm oonnected to each valve and supported by the separating diaphragm7 a spring for moving each valve to its closed position Wiifhinits collapsible diaphragm, there being a pres- 10 sure chamber formed hy each collapsible dia phragm, and a fluid pressure pipe extending from each of the diaphragm chambers arranged to he Connected to a master valve for controlling the pressure in' the diaphragm chambers for opening and closing the valves.

In testimony of which invention, I have hereunto set my hand, at Trenton Y. J., on this 28th day of July, 1922.

CARL R. VALLER. 

